UNIVERSITY    OF    CALIFORNIA     AGRICULTURAL    EXPERIMENT   STATION 

BENJ.    IDE    WHEELER,    PRESIDENT 

COLLEGE   OF  AGRICULTURE  THQMAS  FORSYTH  HUNT    Dean  ano  Director 

BERKELEY  H-    E-   VAN    NORMAN,   Vice-Director   and   Dean 

University  Farm  School 


CIRCULAR  No.  162 
March,  1917 


Bacillary  White  Diarrhoea  or  Fatal 
Septicemia  of  Chicks 

AND 

Coccidiosis  or  Coccidial  Enteritis  of  Chicks 


By  J.  E.  BEACH 


INTRODUCTORY  NOTE 

Bacillary  white  diarrhoea  or  fatal  septicemia,  and  coccidiosis,  or 
coccidial  enteritis,  are  the  two  most  prevalent  and  most  serious  dis- 
eases of  chicks.  In  California  coccidiosis  is  very  prevalent  while  out- 
breaks of  bacillary  white  diarrhoea  are  comparatively  infrequent.  The 
name  "white  diarrhoea"  has  led  to  more  or  less  confusion  in  the 
minds  of  many  poultrymen  regarding  the  exact  nature  of  this  disease. 
Since  any  disorder  of  very  young  chicks  is  liable  to  be  manifested  by 
a  disturbance  of  the  digestive  system  and  consequent  diarrhoea,  with 
thin  yellowish-white  droppings  which  bring  about  a  deposit  of  white 
material  on  the  feathers  below  the  vent,  many  outbreaks  of  so-called 
"white  diarrhoea"  are  in  reality  due  to  errors  in  hatching  or  rearing 
and  in  no  way  related  to  the  infectious  disease,  bacillary  white 
diarrhoea. 

By  some  writers,  coccidia  are  given  as  one  cause  of  "white  diar- 
rhoea" and,  therefore,  coccidiosis  is  classified  as  one  form  of  white 
diarrhoea.  Such  a  classification  has  caused  considerable  confusion 
in  the  minds  of  poultrymen  and  is,  according  to  the  observations  made 
at  this  station,  wholly  unjustifiable.  In  none  of  the  outbreaks  of 
coccidiosis  investigated  by  this  station  have  there  been  any  symptoms 
or  history  which  might  be  confused  with  those  of  bacillary  white 
diarrhoea.  In  the  following  pages  the  two  diseases  are  taken  up 
separately  and  an  attempt  made  to  describe  them  in  such  a  manner 
as  to  avoid  any  confusion  regarding  their  identity. 


BACILLARY  "WHITE  DIARRHOEA  OR  FATAL  SEPTICEMIA  OF  CHICKS 

Character  of  the  Disease. — Bacillary  white  diarrhoea  is  an  in- 
fectious disease  of  young  chicks  caused  by  an  organism  called  Bac- 
terium pullorum.  The  symptoms  are  usually  a  tendency  to  stay 
under  the  hover  or  stand  in  patches  of  sunlight,  followed  by  droopi- 
ness  and  loss  of  appetite,  and  lastly  diarrhoea,  the  droppings  being 
usually  light  colored.  Frequently  the  feathers  below  the  vent  become 
soiled  with  a  chalk-like  deposit  which  in  long-standing  cases  may 
become  as  large  as  a  walnut  and  block  up  the  vent,  a  condition  known 
to  poultrymen  as  pasting  up  behind.  The  disease  usually  makes  its 
appearance  during  the  first  week  after  the  chicks  are  hatched,  but 
the  losses  may  continue  for  four  weeks  or  more  afterward. 

Post-mortem  Lesions. — The  stomach,  gizzard  and  intestines  are 
usually  pale  and  filled  with  a  slimy  fluid.  The  lower  portion  of  the 
intestines  is  sometimes  filled  with  feces  due  to  the  blocking  up  of 
the  vent. 

The  liver  is  either  a  uniform  dull  ochre  color  or  dull  ochre  streaked 
with  bright  red.  This  is  one  of  the  most  prominent  and  constant 
lesions.  The  size  is  usually  normal  and  very  often  the  organ  is  quite 
soft.  The  gall  bladder  is  normal  in  acute  cases,  but  in  cases  of  long 
standing  it  is  distended  with  dark-colored  bile. 

The  heart,  spleen  and  kidneys  are  usually  paler  than  normal,  but 
this  condition  can  be  detected  only  by  a  practiced  eye.  The  lungs 
are  usually  congested. 

There  is  always  an  unabsorbed  yolk  in  the  abdominal  cavity.  This 
is  the  most  characteristic  lesion.  The  amount  varies,  according  to  the 
course  of  the  disease,  from  a  full-sized  yolk  to  a  piece  no  larger  than 
a  pin  head.  The  consistency  of  the  yolk  also  varies  with  the  course 
of  the  disease;  in  the  early  stages  it  is  large  and  watery,  while  in 
the  cases  of  long  standing  it  is  smaller  and  gelatinous  or  cheesy  in 
consistency.    The  color  is  usually  yellow  or  yellowish  brown. 

Diagnosis. — Symptoms  and  lesions  identical  with  those  described 
can  be  produced  by  a  variety  of  causes.  They  include  improper  incu- 
bation, overheating  or  chilling  in  the  brooder  or  in  shipment,  feeding 
too  soon  after  chicks  are  hatched,  and  improper  feeding  or  over- 
feeding. Therefore,  pasting  up  behind  with  chalky  material,  or  the 
presence  of  lesions  similar  to  the  ones  described,  should  not  be  con- 
sidered as  a  positive  indication  that  the  chicks  are  infected  with 
bacillary  white  diarrhoea.  A  positive  diagnosis  can  be  made  only  by 
a  careful  bacteriological  examination  of  a  dead  chick. 

Method  of  Infection. — The  chicks  which  are  infected  with  the 
bacillary  white  diarrhoea  and  do  not  die,  continue  to  harbor  the  germs 


3 

throughout  their  lifetime.  In  hens  such  infection  is  localized  in  the 
ovaries,  in  males  in  the  testicles. 

Such  fowls  usually  give  no  indication  of  the  infection,  arc  appar- 
ently in  perfect  health,1  and  very  often  are  good  layers.  Post-mortem 
examination  of  such  hens  usually  reveals  ovarian  lesions  consisting 
of  cysts  and  discolored  yolks,  although  frequently  a  slight  congestion 
of  the  ovaries  is  the  only  visible  evidence  of  infection  to  be  found. 
In  males,  the  only  lesion  found  is  a  congestion  of  the  testicles  and 
oftentimes  this  is  absent.  Pure  cultures  of  Bacterium  pullorum  can 
be  obtained  from  the  ovaries  or  testicles  of  infected  fowls.  Some  of 
the  eggs  laid  by  infected  fowls  contain  these  germs  in  the  yolk ;  chicks 
hatched  from  such  eggs  are  infected  when  born,  and  the  infected 
chicks  spread  the  contagion  to  the  others.  One  such  eggs  in  an  incu- 
bator would  be  sufficient  to  infect  the  entire  hatch.  Infected  males 
eliminate  the  germs  in  the  spermatic  fluid  and  thereby  infect  hens 
during  the  process  of  breeding.2  Chicks  may  also  be  infected  by 
placing  them  in  contaminated  brooders.  The  most  common  source  of 
infection,  however,  is  hatching  eggs  laid  by  infected  hens. 

Course  and  Prognosis. — As  a  rule,  this  disease  runs  a  very  rapid 
course,  death  taking  place  within  twenty-four  to  forty-eight  hours 
or  less  after  symptoms  are  noticed.  Frequently,  however,  symptoms 
are  present  for  as  long  as  three  weeks  before  death  ensues.  The  per- 
centage of  mortality  is  usually  high,  the  average  being  more  than 
50  per  cent.  Frequently  as  many  as  90  per  cent  of  the  flock  will 
die,  but  occasionally  the  loss  will  be  slight. 

Treatment. — Various  methods  of  treating  bacillary  white  diar- 
rhoea have  been  recommended  from  time  to  time,  but  further  investi- 
gation has  in  all  cases  shown  them  to  be  of  little  value.  At  the  present 
time  there  is  no  satisfactory  method  of  treating  the  sick  chicks. 
Buttermilk  or  sour  skim-milk  seem  to  have  a  beneficial  effect  in  some 
instances,  but  cannot  be  relied  upon  to  check  the  disease  when  once 
it  has  started.  However,  this  is  just  as  satisfactory  as  any  treatment 
yet  suggested,  and  has  the  added  advantage  of  being  an  excellent 
food  for  the  chicks.  Therefore  preventive  measures  are  more  im- 
portant than  treatment  for  controlling  this  disease. 

Preventing  the  Entrance  of  the  Infection  Through  Infected  Eggs. 
— :Obviously,  the  certain  way  of  preventing  eggs  from  infected  hens 
from  getting  in  the  incubator  is  to  use  hatching  eggs  from  flocks 

i  One  outbreak  of  a  disease  of  mature  fowls  in  which  the  percentage  of  mor- 
tality was  high  and  the  cause  of  which  was  Bad.  pullorum  has  been  reported. 
(Jones,  F.  S.,  Report  of  the  N.  Y.  State  Veterinary  College,  1911-12.) 

2  Infected  mature  females  can  also  transmit  the  infection  to  healthy  mature 
females  in  the  same  flock. 


known  to  be  free  from  infection.  If  a  poultry  breeder  has  had  no 
trouble  with  bacillary  white  diarrhoea  in  his  own  chicks  or  in  chicks 
hatched  by  others  from  eggs  produced  by  his  flock,  this  may  be  taken 
as  assurance  that  his  flock  is  not  infected.  It  is  also  possible  to  deter- 
mine positively  whether  or  not  a  flock  is  infected,  either  by  bacterio- 
logical examination  of  the  eggs,  or  by  means  of  a  blood  test  known 
as  the  "macroscopic  agglutination  test."  The  first  method  would 
necessitate  that  the  hens  be  trapnested  and  an  examination  made  of 
each  egg.  Since  an  infected  hen  may  lay  no  more  than  one  infected 
egg  a  month,  or  even  less,  frequently  the  egg  examination  would  have 
to  be  made  daily  for  a  long  period  and  the  amount  of  work  required 
would  make  this  method  impracticable.  The  agglutination  test  has 
been  proved  to  be  reliable  by  numerous  investigators.3  In  Connecti- 
cut and  Rhode  Island  upwards  of  twenty-five  thousand  fowls  have 
been  tested  by  this  method.  To  make  the  test,  a  small  amount  of 
blood  is  drawn  from  the  wing  vein  of  each  fowl.  This  is  forwarded 
to  a  laboratory  where  the  test  is  made.  The  results  of  investigations 
have  shown  that  in  order  to  pick  out  all  the  infected  fowls  two  or 
more  tests  are  necessary.  Since  it  costs  about  ten  cents  per  fowl  to 
make  the  test,  the  necessity  of  making  repeated  tests  would  make  this 
method  too  expensive  for  practical  use.  However,  one  test  will  show 
whether  or  not  the  flock  is  infected  and  herein  lies  its  chief  practical 
value.  If  a  tested  flock  contained  no  reactors  to  one  test,  it  could  be 
considered  as  free  from  infection. 

Preventing  the  Infection  from  Spreading  to  Healthy  Chicks  after 
it  has  Gained  Entrance  to  the  Flock. — To  prevent  the  disease  from 
spreading  after  it  has  gained  entrance  in  a  flock,  all  the  sick  chicks 
should  be  removed  and  destroyed,  the  house  thoroughly  cleaned  and 
disinfected,  thereafter  cleaned  daily,  and  the  chicks  divided  into  small 
flocks,  the  purpose  of  this  being  to  present  a  large  number  of  chicks 
from  becoming  infected  in  case  all  the  infected  chicks  were  not  re- 
moved. An  added  advantage  of  having  the  chicks  in  small  flocks  is 
that  any  new  cases  that  develop  can  be  more  easily  detected. 

Preventing  Chicks  Hatched  from  Non-infected  Eggs  from  Be- 
coming Infected. — The  ways  in  which  non-infected  chicks  could  be 
infected  after  being  put  in  the  brooder  house  would  be  by  placing 
them  in  a  contaminated  brooder  or  by  the  infection  being  carried  in 
from  infected  flocks.  Since  the  white  diarrhoea  germs  are  compar- 
atively easy  to  kill,  a  thorough  cleaning  and  disinfection  of  the 
brooder  before  the  chicks  are  put  in  will  destroy  all  infection;  and, 
if  care  is  taken  to  prevent  the  infection  being  carried  in  from  diseased 
flocks  by  visitors,  attendants,  dogs,  etc.,  there  is  little  danger  of  the 
flock  becoming  infected. 

Results  of  the  Use  of  the  Agglutination  Test  at  this  Station  on  a 
Small  Number  of  Birds  from  Two  Different  Flocks. — Flock  No.  1 :  In 
June,  1914,  two  dead  chicks  were  brought  to  the  Veterinary  Science 

3  Jones,  Report  of  N.  Y.  State  Vet.  College,  1911-12,  Journal  of  American 
Society  of  Instructors  and  Investigators  in  Poultry  Husbandry,  1916;  Gage, 
Mass.  Agr.  Exp.  Station,  Bui.  148,  1914;  Rettger,  Kirkpatrick  and  Jones,  Storrs 
Agr.  Exp.  Station,  Bui.  185,  1915;  and  others. 


Laboratory  for  diagnosis.  The  owner  reported  that  a  majority  of  the 
chicks  he  had  hatched  that  year  had  died  when  they  were  a  few  days 
old.  A  bacteriological  examination  of  these  chicks  resulted  in  the 
isolation  in  pure  culture  from  the  heart  blood  and  liver  of  Bacterium 
pullorum  and,  therefore,  the  disease  was  diagnosed  as  bacillary  white 
diarrhoea.  On  inquiry  it  was  learned  that  the  chicks  were  hatched 
from  eggs  produced  on  the  premises.  Therefore,  it  seemed  probable 
that  the  hens  were  the  source  of  the  infection  and  it  was  decided  to 
attempt  to  pick  out  the  mature  fowls  that  were  infected  by  means 
of  the  agglutination  test.  It  was  not  possible  to  obtain  permission 
of  the  owner  to  test  more  than  four  of  the  hens,  and  a  small  quantity 
of  blood  was  drawn  from  the  wing  vein  of  each  of  the  four  fowls  and 
the  test  made.  Three  of  the  hens  reacted  and  one  gave  no  reaction. 
Two  of  the  reactors,  and  the  non-reactor  were  procured  from  the 
owner  and  a  post-mortem  examination  made.  The  ovaries  of  both  of 
the  reactors  were  found  to  be  diseased  and  pure  cultures  of  Bacterium 
pullorum  were  obtained.    The  ovaries  of  the  non-reactor  were  normal. 

Flock  No.  2 :  In  August,  1916,  a  poultry  raiser  reported  a  disease 
among  his  chicks  which  upon  investigation  proved  to  be  bacillary 
white  diarrhoea.  Arrangements  were  then  made  to  test  some  of  the 
hens  of  the  flock  which  produced  the  eggs  from  which  the  chicks 
were  hatched.  One  hundred  fowls  were  tested.  About  65  per  cent 
gave  positive  reaction.  Several  of  the  fowls  were  then  killed  and 
post-mortem  examinations  made.  All  the  reactors  killed  had  diseased 
ovaries  while  the  ovaries  of  all  of  the  non-reactors  were  perfectly 
normal.  As  far  as  could  be  determined  by  outward  appearance,  all 
the  fowls  tested  were  in  perfect  health. 

Fifty  more  fowls  from  this  same  flock  were  tested  in  February, 
1917,  50  per  cent  giving  positive  reactions.  Post-mortem  examin- 
ations were  made  of  none  of  these  fowls.  All  were  apparently  in 
perfect  health. 

COCCIDIOSIS  IN  CHICKS    . 

Coccidiosis  or  coccidial  enteritis  is  an  infectious  disease  of  chicks 
caused  by  protozoon  organisms  known  as  coccidia  (Coccidium  tenel- 
lum).  The  intestines  are  usually  the  only  organs  infected,  but  occa- 
sionally lesions  are  found  in  the  liver  or  lungs  and  other  organs. 
Coccidia  may  exist  in  small  numbers  in  the  intestines  of  chicks 
without  causing  any  apparent  harm,  but  when  they  are  present  in 
sufficient  numbers  they  destroy  the  mucous  membrane  lining  of  the 
intestines  and  death  results.  The  caeca  or  " blind  guts"  are  the 
portions  of  the  intestines  most  seriously  affected.  The  disease  is 
seldom  seen  in  chicks  under  two  weeks  or  over  four  months  of  age. 

The  usual  history  of  outbreaks  of  coccidiosis  is  that  the  chicks  do 
well  until  they  are  a  few  weeks  old,  when  they  begin  to  look  un- 
thrifty, droop  and  gradually  die.  It  is  not  at  all  uncommon  for  entire 
flocks  of  chicks  to  die  in  the  course  of  a  month  or  six  weeks.  The 
symptoms  of  the  disease  do  not  differ  materially  from  those  of  some 
other  diseases  and  are,  therefore,  merely  suggestive  of  coccidiosis. 


The  feathers  of  sick  chicks  become  ruffled  and  soiled;  there  is  a 
marked  paleness  of  the  skin  of  the  head  and  of  the  visible  mucous 
membranes.  The  sick  chicks  are  inclined  to  separate  themselves  from 
the  rest  of  the  flock  and  stand  "humped  up"  with  their  eyes  closed 
for  hours  at  a  time  unless  disturbed.  Usually  diarrhoea,  which  is 
sometimes  bloody,  is  present.  A  bloody  diarrhoea  can  be  considered 
as  positive  evidence  of  coccidial  infection.  Chicks  usually  show 
symptoms  for  at  least  three  or  four  days  before  death  occurs. 

The  post-mortem  lesions  usually  consist  of  an  enlargement  of  the 
caeca.  The  contents  of  the  enlarged  caeca  may  be  either  normal  in 
consistency  and  brown  or  reddish-brown  in  color,  semiliquid  and 
bloody,  or  solid  and  yellowish  white,  brown  or  red  in  color.  Occa- 
sionally there  is  no  enlargement  of  the  caeca  nor  abnormal  appearance 
of  the  contents,  so  the  absence  of  enlarged  caeca  cannot  be  taken  as 
an  indication  that  the  chicks  are  not  infected  with  coccidiosis.  Fre- 
quently there  is  an  inflammation  of  the  lining  of  the  intestines 
throughout  their  entire  length.  All  other  organs  are,  in  most  cases, 
apparently  normal.  Symptoms  and  lesions  very  similar  to  these, 
however,  may  be  produced  by  causes  other  than  coccidiosis ;  therefore, 
a  microscopical  examination  is  necessary  for  a  positive  diagnosis.  If 
coccidia  are  the  cause  they  will  be  found  in  large  numbers  when  the 
contents  of  the  intestines  are  examined  microscopically.  Coccidiosis 
is  spread  by  the  organisms  which  pass  out  with  the  droppings  of 
diseased  birds.  Other  chicks  become  infected  by  drinking  water  or 
eating  food,  litter,  or  particles  of  soil  contaminated  by  the  droppings 
from  diseased  chicks.  It  has  been  demonstrated  that  these  organisms 
will  remain  alive  in  soil  for  a  year  or  more.  Therefore,  chicks  that 
are  allowed  to  run  in  yards  in  which  infected  chicks  were  kept  the 
year  previous  are  very  likely  to  become  infected. 

There  are  no  drugs  which  have  been  found  to  be  practical  for 
treating  diseased  chicks.  Seemingly  good  results  were  obtained  by 
emetine  hydrochloride,  but  the  cost  of  this  drug  prohibits  its  use.  It 
is  known,  however,  that  the  presence  of  acid  and  a  perfectly  healthy 
condition  of  the  mucous  membrane  of  the  intestines  inhibits  the 
multiplication  of  these  organisms  and  it  is  also  known  that  unless 
they  are  present  in  large  numbers  very  little  damage  is  done.  There- 
fore, the  disease  can  be  controlled  if  the  mucous  membrane  is  kept 
in  a  perfectly  healthy  condition  and  the  intestinal  contents  acid. 
These  conditions  may  be  brought  about  by  feeding  the  chicks  spar- 
ingly of  grain  and  mash  (a  superabundance  of  food  in  the  intestines 
causes  malfermentation  which  lowers  the  resistance  of  the  tissues  to 
the  action  of  the  organisms),  and  by  feeding  sour  milk  or  butter- 
milk in  large  quantities,  the  lactic  acid  in  the  milk  inhibiting  the 
multiplication  of  the  organisms.  Good  results  can  sometimes  be 
obtained  by  giving  hydrochloric  acid  in  the  drinking  water,  one 
teaspoonful  of  the  acid  per  quart  of  water.  If  buttermilk  or  sour 
milk  is  unobtainable  hydrochloric  acid  may  therefore  be  used.  Every 
effort  to  obtain  sour  milk  should  be  made,  however. 

Investigation  at  this  station  has  shown  that  the  above  measures 
can  be  put  into  successful  practical  application  and  that  the  follow- 


ing  sanitary  measures  and  feeding  method  are  an  efficient  means  for 
controlling  the  disease  : 

Sanitary  Measures. — If  only  a  few  chicks  are  visibly  sick  when 
the  presence  of  the  disease  is  discovered,  remove  them  from  the  flock 
and  either  keep  them  isolated  or  kill  and  burn  them,  preferably  the 
latter.  If.  however,  a  large  percentage  of  the  flock  are  visibly  in- 
fected, remove  only  the  worst  cases,  which  should  be  killed  and 
burned. 

If  possible,  put  the  chicks  on  new  ground.  If  this  is  not  possible, 
plow  or  spade  the  yards.  Thoroughly  clean  the  houses  with  a  strong 
hot  disinfectant  solution.  After  the  floors  have  dried  cover  them 
with  a  thin  layer  of  litter  (shavings,  chopped  alfalfa  hay  or  straw). 
Sweep  out  this  litter  daily,  burn  it  and  put  fresh  litter  in  the  houses. 
The  litter  will  collect  the  droppings,  thus  preventing  them  from 
sticking  to  the  floor,  and  making  the  daily  cleaning  easy.  Continue 
this  daily  cleaning  until  the  chicks  are  old  enough  to  roost,  and  for 
a  longer  period  if  all  signs  of  the  disease  have  not  disappeared.  If 
all  signs  of  the  disease  have  disappeared  by  the  time  the  chicks  are 
old  enough  to  roost,  deep  litter  can  be  put  in  the  houses  and  the 
daily  cleaning  confined  to  the  dropping  boards  underneath  the  roosts. 
It  is  advisable  to  exclude  the  chicks  from  the  dropping  boards  by 
means  of  wire  netting.  Keep  all  feeding  and  drinking  vessels  scrupu- 
lously clean  at  all  times. 

Feeding  Method. — Feed  a  small  amount  of  grain  night  and 
morning.  Feed  mash  during  the  middle  of  the  day,  never  leaving  it 
before  the  chicks  longer  than  two  hours.4  Feed  greens  as  usual.  Keep 
buttermilk  in  fountains  constantly  before  the  chicks.  The  restricted 
grain  ration  will  keep  the  chicks  hungry  and  they  will  consume  large 
quantities  of  buttermilk.  If  too  much  grain  and  mash  are  fed  and 
the  chicks  drink  large  quantities  of  buttermilk,  sour  crop  is  very  liable 
to  result.  There  is  no  danger  of  this  occurring,  however,  if  the 
amount  of  grain  fed  is  small. 

In  most  instances,  if  the  above  sanitary  measures  and  feeding 
method  are  carefully  followed,  improvement  in  the  condition  of  the 
flock  will  be  noticeable  in  three  or  four  days  and  all  signs  of  the 
disease  will  have  disappeared  in  from  two  to  four  weeks.  The  butter- 
milk will  cause  the  droppings  to  be  somewhat  "watery,"  but  this 
should  not  be  considered  as  being  at  all  dangerous. 

The  above  feeding  methods  should  be  employed  from  the  start, 
when  chicks  are  put  in  houses  and  yards  in  which  a  flock  infected 
with  coccidia  was  kept  the  year  before.  Buttermilk  has  considerable 
food  value,  so  that  normal  growth  and  development  will  be  obtained. 

Report  of  Three  Outbreaks  of  Coccidiosis  Successfully  Controlled. 
— Three  outbreaks  ol  coccidiosis  at  this  station  have  been  successfully 
controlled  by  the  employment  of  the  above  described  sanitary  precau- 
tions and  feeding  method.  The  first  outbreak  occurred  in  April,  1915, 
in  a  flock  of  150  chicks,  five  and  one-half  weeks  old.  The  presence  of 
the  disease  was  shown  by  some  bloody  droppings  which  upon  micro- 

*  In  severe  outbreaks  withhold  the  mash  entirely  until  the  condition  of  the 
flock  shows  marked  improvement. 


8 

scopical  examination  were  found  to  contain  large  numbers  of  coccidia. 
The  flock  was  then  carefully  examined  and  eight  chicks  picked  out 
as  visibly  sick.  They  were  at  once  isolated.  A  microscopic  examin- 
ation of  the  droppings  of  each  of  these  eight  chicks  showed  them  to 
contain  large  numbers  of  coccidia.  Although  all  the  visibly  sick 
chicks  had  been  removed,  bloody  droppings  containing  large  numbers 
of  coccidia  continued  to  appear  on  the  dropping  boards.  This  showed 
that  although  there  were  no  visibly  sick  chicks  in  the  flock  there  were 
some  badly  infected  ones  and  that  it  was  impossible  to  remove  all  the 
infected  chicks  by  the  isolation  of  all  visibly  sick. 

The  daily  cleaning  of  the  houses  and  "buttermilk  diet"  were  then 
adopted.  No  more  visibly  sick  chicks  were  noticed,  and  at  the  end 
of  three  weeks  all  evidence  of  the  disease  had  disappeared.  The 
chicks  also  showed  normal  growth,  many  of  them  weighing  1%  pounds 
at  nine  weeks  of  age. 

The  second  outbreak  occurred  in  April,  1916,  in  a  flock  of  150 
one-month-old  chicks  which  were  kept  in  the  same  yard  as  the  flock 
just  described.  More  than  half  of  the  chicks  were  visibly  sick  when 
the  presence  of  the  disease  was  discovered.  The  procedure  for  con- 
trolling the  disease  was  the  same  as  in  the  previous  outbreak  with 
the  exception  that  none  of  the  sick  chicks  was  removed.  A  decided 
improvement  in  the  condition  of  the  flock  was  noticed  within  three 
days,  and  all  evidence  of  the  disease  had  disappeared  a  month  later. 
Only  one  chick  died  from  coccidiosis. 

The  third  outbreak  occurred  in  January,  1917,  in  a  flock  of  730 
two-months-old  chicks.  About  60  per  cent  of  the  flock  were  visibly 
sick  when  the  presence  of  the  disease  was  discovered.  Post-mortem 
examinations  of  several  of  the  dead  chicks  showed  the  lesions  in  the 
caeca  to  be  unusually  severe.  The  control  measures  for  this  flock 
varied  somewhat  from  those  used  in  the  previous  outbreaks.  The 
brooder  house  was  immediately  cleaned  and  disinfected  and  there- 
after cleaned  every  other  day  instead  of  daily.  A  small  quantity  of 
grain  was  fed  night  and  morning,  but  no  mash  was  fed  at  any  time. 
Buttermilk  in  fountains  was  kept  constantly  before  the  chicks.  This 
much  restricted  grain  ration  kept  the  chicks  very  hungry  and  they 
consumed  about  forty  gallons  of  buttermilk  daily.  Almost  immediate 
improvement  in  the  condition  of  the  flock  was  noticed  and  in  less 
than  three  weeks  all  evidence  of  the  disease  had  disappeared.  The 
entire  loss  by  death  was  only  thirty-five  chicks.  The  above  described 
control  measures  were  carried  out  for  three  weeks  when  the  chicks 
were  placed  in  colony  houses,  mash  again  fed,  and  the  amount  of 
buttermilk  given  greatly  reduced.  All  the  chicks  made  normal 
growth. 


